McCABE-THIELE METHOD FOR TRAYED TOWERS

Your objectives in studying this section are to be able to  

Understand the fundamentals of the McCabe-Thiele graphical method to analyze binary distillation in trayed towers. 

Apply the McCabe-Thiele graphical method to determine the number of equilibrium stages required for a given separation and the optimal location along the cascade for introduction of the feed. 

The McCabe-Thiele method hinges upon the fact that, as an approximation, the operating lines on the xy diagram can be considered straight for each section of a fractionator between points of addition or withdrawal of streams. This is true only if the total molar flow rates of liquid and vapor do not vary from stage to stage in each section of the column. This is the case if  

The two components have equal and constant molar latent heats of vaporization. 

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